A RARE AND UNUSUAL PALLASITE FROM BIG SKY COUNTRY

Every detail about Choteau makes it clear that this is an unbelievably special meteorite. First, it is one of only seven meteorites found in Montana. In addition, it is the only pallasite ever found in Big Sky Country. On top of that, it is one of only 13 ungrouped pallasites, which in this case means that it shares some of its chemical properties with the acapulcoite and lodranite primitive achondrites. And finally, only a single 8.4 kg (18.5 pound) stone was found, meaning that there will only ever be a very small number of Choteau slices available to the public. The remarkable size of some of Choteau's honey-colored olivine crystals, combi♚ned with the distinct Widmanstätten patterning of its iron-nickel matrix, combine with all of its other distinctions to make this a rare, important, and highly collectible meteorite.

Pallasites such as Choteau are incredible rare, accounting for .2% — or just 1 out of 500 — of all meteorite 🦩finds. A number of the olivine crystals found embedded in this slice of Choteau are unbelievably large, the remnants of pieces of an asteroid's stony mantle becoming suspended in the molten metal of its iron-nickel core. The Widmanstätten pattern seen on the display side of this meteorite slice is the result of slow cooling over millions of years, providing sufficient time for the two iron-nickel alloys present in the meteorite to orient into a crystalline habit. As Widmanstätten patterns can only occur within certain types of asteroids in the vacuum of space, their presence is diagnostic in the identification of a meteorit﷽e.

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